Table 3.
Obstructive sleep apnea parameters—exploratory comparisons
| Characteristic | Placebo | Pimavanserin | P Value |
|---|---|---|---|
| AHI, events/h | 30.5 (28.6) | 17.9 (39.5) | 0.284 |
| AHI4, events/h | 8.8 (23.8) | 6.5 (18.7) | 0.119 |
| AHI supine, events/h | 27.4 (42.4) | 31 (32.0) | 0.963 |
| Supine sleep, % total sleep time | 72.9 (46.1) | 81.1 (41.1) | 0.339 |
| NREM AHI supine, events/h | 29.5 (27.3) | 17.6 (40.5) | 0.325 |
| REM AHI supine, events/h* | 32.2 (38.5) | 43.4 (34.6) | 0.893 |
| Total sleep time, min | 285.5 ± 94.4 | 325.0 ± 73.5 | 0.007 |
| Sleep efficiency | 75.1 (13.3) | 83.8 (17.7) | 0.108 |
| N1, % total sleep time | 34.1 ± 19.4 | 29.0 ± 17.6 | 0.179 |
| N2, % total sleep time | 48.1 ± 15.8 | 49.7 ± 14.6 | 0.652 |
| N3, % total sleep time | 5.1 (8.3) | 10.4 (16.6) | 0.120 |
| REM sleep, % total sleep time | 10.5 (14.2) | 7.2 (9.0) | 0.551 |
| Arousal index, events/h | 41.0 ± 21.5 | 37.9 ± 21.9 | 0.524 |
| Respiratory event duration, s | 29.2 ± 7.5 | 30.1 ± 6.7 | 0.565 |
| O2 desaturation index, events/h | 18.7 (31.1) | 11.3 (12.8) | 0.142 |
| Mean O2 saturation during sleep, % | 93.9 ± 2.3 | 93.9 ± 2.5 | 0.552 |
| Nadir O2 saturation, % | 86 (11) | 82 (13) | 0.073 |
| Hypoxic burden, %min/h | 51.4 (63.2) | 38.1 (56.1) | 0.130 |
| Sleep time spent <90% SpO2, % total | 0.7 (4.1) | 1.9 (6.2) | 0.678 |
| Estimated stable sleep time, min | 202.5 ± 97.1 | 243.9 ± 88.2 | 0.040 |
| Systolic blood pressure, mm Hg | 130.7 ± 16.2 | 131.4 ± 14.5 | 0.825 |
| Diastolic blood pressure, mm Hg | 72.2 ± 11.2 | 74.7 ± 10.7 | 0.255 |
| Heart rate, beats/min | 67.8 ± 11.1 | 82.4 ± 18.3 | 0.085 |
| Visual Analog Scale for sleep quality | 6 (2) | 5 (1) | 0.013 |
Definition of abbreviations: AHI = apnea–hypopnea index; AHI4 = number of events per hour associated with 4% oxygen desaturation; NREM = non-REM; REM = rapid eye movements.
Data are mean ± standard deviation or median (interquartile range) when appropriate and were compared with a two-tailed paired Student’s t test or a Wilcoxon signed-rank test according to statistical distribution. Blood pressure, heart rate, and Visual Analog Scale for Sleep Quality measurements refer to next-day values. Stable sleep time was estimated by subtracting from total sleep time the number of events per hour multiplied by their average duration.
Values were not available for four patients on placebo (three patients did not have REM) and two on pimavanserin (both without REM).